An N-Level Flying Capacitor Based Active Neutral-Point-Clamped Converter,
2010
University of Sydney
An N-Level Flying Capacitor Based Active Neutral-Point-Clamped Converter, Sridhar R. Pulikanti, Georgios S. Konstantinou, Vassilios G. Agelidis
Faculty of Engineering and Information Sciences - Papers: Part A
An n-level flying capacitor (FC) based active neutral point clamped (ANPC) converter is discussed in this paper. The converter is based on an arrangement of a three-level ANPC converter and a number of two-level cells creating an n-level line-to-neutral waveform. The converter is operated under a phase-shifted carrier pulse-width modulation (PWM). The mathematical model for the DC-link capacitors voltage behavior of a three-phase arrangement is also presented. It is shown through simulations and experimental work that the voltage of flying capacitors can naturally balance to the required level in order to generate multilevel waveform. Simulations and experimental work of a …
Harmonic Elimination Control Of A Five-Level Dc-Ac Cascaded H-Bridge Hybrid Inverter,
2010
University Of New South Wales
Harmonic Elimination Control Of A Five-Level Dc-Ac Cascaded H-Bridge Hybrid Inverter, Georgios S. Konstantinou, Sridhar R. Pulikanti, Vassilios G. Agelidis
Faculty of Engineering and Information Sciences - Papers: Part A
A five-level hybrid cascaded inverter operating under selective harmonic elimination (SHE) pulse-width modulation (PWM) control is discussed in this paper. The topology is a cascaded connection of a conventional three-phase, two-level inverter and an H-bridge module for each phase with a single DC-source. The topology boosts the output voltage within limits and with no additional DC-DC converters. However, such boosting feature depends on the control of the floating capacitor voltage and the load power factor. The regulation of the floating capacitor for the given modulation strategy is also analyzed. Experimental results taken from a single-phase laboratory prototype are presented to …
The Impact Of Strategy And Maturity On Business Analytics And Firm Performance: A Review And Research Agenda,
2010
University of Melbourne
The Impact Of Strategy And Maturity On Business Analytics And Firm Performance: A Review And Research Agenda, Graeme Shanks, Rajeev Sharma, Peter Seddon, Peter Reynolds
Faculty of Engineering and Information Sciences - Papers: Part A
Business analytics involves interpreting organizational data to improve decision-making and to optimise business processes. It has the potential to improve firm performance and increase competitive advantage. Although many case studies have been reponed that describe business analytics applications and speculate about how they might contribute to firm performance, there is no clearly articulated and theoretically grounded model in the literature. This paper proposes a theoretical framework jor understanding how and why business analytics technology and capabilities can lead to value-creating actions that lead to improved form performance and competitive advantage. We jocus particularly on how strategy and maturity impact business …
Seven-Level Cascaded Anpc-Based Multilevel Converter,
2010
University of Sydney
Seven-Level Cascaded Anpc-Based Multilevel Converter, Sridhar R. Pulikanti, Georgios S. Konstantinou, Vassilios G. Agelidis
Faculty of Engineering and Information Sciences - Papers: Part A
A seven-level converter based on the cascaded connection of a three-level active neutral-point-clamped (ANPC) converter and individual H-bridge cells per phase is presented in this paper. This converter only requires a single DC source for all three phases and extends the amplitude of output voltage of the converter with similar DC-link voltage. The operation principles and control strategies based on a fundamental frequency harmonic elimination PWM are discussed. The regulation of FC voltage depends on the positions of switching angles over a quarter period in the available solutions and on the load power factor. In order to extend the regulation …
Feature Selection With Redundancy-Constrained Class Separability,
2010
Australian National University
Feature Selection With Redundancy-Constrained Class Separability, Luping Zhou, Lei Wang, Chunhua Shen
Faculty of Engineering and Information Sciences - Papers: Part A
Scatter-matrix-based class separability is a simple and efficient feature selection criterion in the literature. However, the conventional trace-based formulation does not take feature redundancy into account and is prone to selecting a set of discriminative but mutually redundant features. In this brief, we first theoretically prove that in the context of this trace-based criterion the existence of sufficiently correlated features can always prevent selecting the optimal feature set. Then, on top of this criterion, we propose the redundancy-constrained feature selection (RCFS). To ensure the algorithm's efficiency and scalability,we study the characteristic of the constraints with which the resulted constrained 0-1 …
Efficient Structured Support Vector Regression,
2010
Australian National University
Efficient Structured Support Vector Regression, Ke Jia, Lei Wang, Nianjun Liu
Faculty of Engineering and Information Sciences - Papers: Part A
Support Vector Regression (SVR) has been a long standing problem in machine learning, and gains its popularity on various computer vision tasks. In this paper, we propose a structured support vector regression framework by extending the max-margin principle to incorporate spatial correlations among neighboring pixels. The objective function in our framework considers both label information and pairwise features, helping to achieve better cross-smoothing over neighboring nodes. With the bundle method, we effectively reduce the number of constraints and alleviate the adverse effect of outliers, leading to an efficient and robust learning algorithm. Moreover, we conduct a thorough analysis for the …
Efficient Spectral Feature Selection With Minimum Redundancy,
2010
Arizona State University
Efficient Spectral Feature Selection With Minimum Redundancy, Zheng Zhao, Lei Wang, Huan Liu
Faculty of Engineering and Information Sciences - Papers: Part A
Spectral feature selection identifies relevant features by measuring their capability of preserving sample similarity. It provides a powerful framework for both supervised and unsupervised feature selection, and has been proven to be effective in many real-world applications. One common drawback associated with most existing spectral feature selection algorithms is that they evaluate features individually and cannot identify redundant features. Since redundant features can have significant adverse effect on learning performance, it is necessary to address this limitation for spectral feature selection. To this end, we propose a novel spectral feature selection algorithm to handle feature redundancy, adopting an embedded model. …
A Multi-Resolution Approach To Learning With Overlapping Communities,
2010
Arizona State University
A Multi-Resolution Approach To Learning With Overlapping Communities, Lei Tang, Xufei Wang, Huan Liu, Lei Wang
Faculty of Engineering and Information Sciences - Papers: Part A
The recent few years have witnessed a rapid surge of par- ticipatory web and social media, enabling a new laboratory for studying human relations and collective behavior on an unprecedented scale. In this work, we attempt to harness the predictive power of social connections to determine the preferences or behaviors of individuals such as whether a user supports a certain political view, whether one likes one product, whether he/she would like to vote for a presidential candidate, etc. Since an actor is likely to participate in mul- tiple dierent communities with each regulating the actor's behavior in varying degrees, and …
A Scalable Algorithm For Learning A Mahalanobis Distance Metric,
2010
National ICT Australia
A Scalable Algorithm For Learning A Mahalanobis Distance Metric, Junae Kim, Chunhua Shen, Lei Wang
Faculty of Engineering and Information Sciences - Papers: Part A
A distance metric that can accurately re°ect the intrinsic characteristics of data is critical for visual recognition tasks. An e®ective solution to de¯ning such a metric is to learn it from a set of training sam- ples. In this work, we propose a fast and scalable algorithm to learn a Ma- halanobis distance. By employing the principle of margin maximization to secure better generalization performances, this algorithm formulates the metric learning as a convex optimization problem with a positive semide¯nite (psd) matrix variable. Based on an important theorem that a psd matrix with trace of one can always be represented …
Balanced Truncation Of Linear Second-Order Systems: A Hamiltonian Approach,
2010
Freie Universitat Berlin
Balanced Truncation Of Linear Second-Order Systems: A Hamiltonian Approach, Carsten Hartmann, Valentina-Mira Vulcanov, Christof Schutte
Faculty of Engineering and Information Sciences - Papers: Part A
We present a formal procedure for structure-preserving model reduction of linear second-order and Hamiltonian control problems that appear in a variety of physical contexts, e.g., vibromechanical systems or electrical circuit design. Typical balanced truncation methods that project onto the subspace of the largest Hankel singular values fail to preserve the problem's physical structure and may suffer from lack of stability. In this paper, we adopt the framework of generalized Hamiltonian systems that covers the class of relevant problems and that allows for a generalization of balanced truncation to second-order problems. It turns out that the Hamiltonian structure, stability, and passivity …
Hippocampal Shape Classification Using Redundancy Constrained Feature Selection,
2010
Australian National University
Hippocampal Shape Classification Using Redundancy Constrained Feature Selection, Luping Zhou, Lei Wang, Chunhua Shen, Nick Barnes
Faculty of Engineering and Information Sciences - Papers: Part A
Landmark-based 3D hippocampal shape classification involves high-dimensional descriptor space, many noisy and redundant features, and a very small number of training samples. Feature selection becomes critical in this situation, because it not only improves classification performance, but also identifies the regions that contribute more to shape discrimination. This work identifies the drawbacks of SVM-RFE, and proposes a novel class-separability-based feature selection approach to overcome them. We formulate feature selection as a constrained integer optimization and develop a new algorithm to efficiently and optimally solve this problem. Theoretical analysis and experimental study on both synthetic data and real hippocampus data demonstrate …
On Pogorelov Estimates For Monge-Ampere Type Equations,
2010
University of Wollongong
On Pogorelov Estimates For Monge-Ampere Type Equations, Jiakun Liu, Neil Trudinger
Faculty of Engineering and Information Sciences - Papers: Part A
In this paper, we prove interior second derivative estimates of Pogorelov type for a general form of Monge-Ampère equation which includes the optimal transportation equation. The estimate extends that in a previous work with Xu-Jia Wang and assumes only that the matrix function in the equation is regular with respect to the gradient variables, that is it satisfies a weak form of the condition introduced previously by Ma,Trudinger and Wang for regularity of optimal transport mappings. We also indicate briefly an application to optimal transportation.
Twisted Cyclic Theory And An Index Theory For The Gauge Invariant Kms State On Cuntz Algebras On,
2010
Australian National University
Twisted Cyclic Theory And An Index Theory For The Gauge Invariant Kms State On Cuntz Algebras On, Alan L. Carey, John Phillips, Adam C. Rennie
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents, by example, an index theory appropriate to algebras without trace. Whilst we work exclusively with the Cuntz algebras the exposition is designed to indicate how to develop a general theory. Our main result is an index theorem (formulated in terms of spectral flow) using a twisted cyclic cocycle where the twisting comes from the modular automorphism group for the canonical gauge action on the Cuntz algebra. We introduce a modified K1-group of the Cuntz algebra so as to pair with this twisted cocycle. As a corollary we obtain a noncommutative geometry interpretation for Araki's notion of relative …
Coastal Reservoir In Murray-Darling River And Its Useful Experience For Yellow River,
2010
University of Wollongong
Coastal Reservoir In Murray-Darling River And Its Useful Experience For Yellow River, Shu-Qing Yang
Faculty of Engineering and Information Sciences - Papers: Part A
this paper deals with the similarities between the Yellow River Basin and Murray - Darling River Basin. It is found that two of them are facing similar problems, such as water shortage, poor quality for water supply and decreasing runoff etc. Two basins suffer the sharp temporal and spatial variation in water resources, which results in flood threat and water stress alternatively. Consequently these two rivers have attracted global attention due to their significant impacts on their local economical development and ecological system. To alleviate the water stress conditions, this paper investigates the feasibility of coastal reservoirs at the river …
Flicker Mitigation Strategy For Dfigs During Variable Wind Conditions,
2010
Queen's University of Belfast
Flicker Mitigation Strategy For Dfigs During Variable Wind Conditions, Lasantha Meegahapola, Brendan Fox, Damian Flynn
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents a flicker mitigation scheme for the doubly-fed induction generator (DFIG) during variable wind conditions. The flicker mitigation strategy was developed based on the distribution line X/R ratio and the active power deviation from the average active power during variable wind conditions. Flicker emission was analyzed using a flicker meter based on the IEC standards. Both short-term and long-term flicker severities were analyzed during the time period of study. The flicker mitigation strategy was evaluated under different system conditions such as X/R ratio, distribution line length, shortcircuit capacity (SCC), and wind variability. It is shown that the proposed …
Compressive Evaluation In Human Motion Tracking,
2010
Australian National University
Compressive Evaluation In Human Motion Tracking, Yifan Lu, Lei Wang, Richard Hartley, Hongdong Li, Dan Xu
Faculty of Engineering and Information Sciences - Papers: Part A
The powerful theory of compressive sensing enables an efficient way to recover sparse or compressible signals from non-adaptive, sub-Nyquist-rate linear measurements. In particular, it has been shown that random projections can well approximate an isometry, provided that the number of linear measurements is no less than twice of the sparsity level of the signal. Inspired by these, we propose a compressive anneal particle filter to exploit sparsity existing in image-based human motion tracking. Instead of performing full signal recovery, we evaluate the observation likelihood directly in the compressive domain of the observed images. Moreover, we introduce a progressive multilevel wavelet …
Head Pose Estimation Based On Extended Non-Negative Matrix Factorization,
2010
University of Wollongong
Head Pose Estimation Based On Extended Non-Negative Matrix Factorization, Ce Zhan, Wanqing Li, Philip Ogunbona
Faculty of Engineering and Information Sciences - Papers: Part A
One popular solution to head pose estimation is to formulate it as a pattern classication problem, and treat the holistic facial appearance as the input to classiers. However, since the face appearance contains all kinds of information, the variation caused by other factors such as identity, expression and lighting may be larger than that caused by dierent head poses. Thus, the key challenge of these appearance based methods lies in constructing a feature subspace that could successfully recovers head pose while ignoring other sources of image variation. In this paper, following the intuition of combining parts to form a whole …
Liner Shipping Fleet Deployment With Cargo Transshipment And Demand Uncertainty,
2010
National University of Singapore
Liner Shipping Fleet Deployment With Cargo Transshipment And Demand Uncertainty, S Wang, Q Meng
Faculty of Engineering and Information Sciences - Papers: Part A
This paper addresses a novel liner shipping fleet deployment problem characterized by cargo transshipment, multiple container routing options and uncertain demand, with the objective of maximizing the expected profit. This problem is formulated as a stochastic program and solved by the sample average approximation method. In this technique the objective function of the stochastic program is approximated by a sample average estimate derived from a random sample, and then the resulting deterministic program is solved. This process is repeated with different samples to obtain a good candidate solution along with the statistical estimate of its optimality gap. We apply the …
Investigation Of High Resolution Compact Gamma Camera Module Based On A Continuous Scintillation Crystal Using A Novel Charge Division Readout Method,
2010
Chinese Academy Of Sciences
Investigation Of High Resolution Compact Gamma Camera Module Based On A Continuous Scintillation Crystal Using A Novel Charge Division Readout Method, Qiu-Sheng Dai, Cui-Lan Zhao, Hualin Zhang, Yujin Qi
Faculty of Engineering and Information Sciences - Papers: Part A
The objective of this study is to investigate a high performance and lower cost compact gamma camera module for a multi-head small animal SPECT system. A compact camera module was developed using a thin Lutetium Oxyorthosilicate (LSO) scintillation crystal slice coupled to a Hamamatsu H8500 position sensitive photomultiplier tube (PSPMT). A two-stage charge division readout board based on a novel sub-tractive resistive readout with a truncated center-of-gravity (TCOG) positioning method was developed for the camera. The performance of the camera was evaluated using a flood 99mTc source with a four-quadrant bar-mask phantom. The preliminary experimental results show that the image …
Stabilisation Of An Erodible Soil Using A Chemical Admixture,
2010
University of Wollongong
Stabilisation Of An Erodible Soil Using A Chemical Admixture, Jayan S. Vinod, B Indraratna, Md A. Al Mahamud
Faculty of Engineering and Information Sciences - Papers: Part A
Internal erosional behaviour of a lignosulfonate-treated dispersive soil has been studied using apparatus designed and built at University of Wollongong. The effectiveness of lignosulfonate-treated dispersive clay on its erosion resistance has been investigated and its advantages over traditional admixtures (cement) have been presented. Lignosulfonate is a non-toxic admixture that can stabilise certain erodible and dispersive soils effectively, without causing any adverse environmental impact on the ground unlike some traditional stabilisers. Test results show that the erosional parameters such as critical shear stress and coefficient of soil erosion are improved with the increase in the amount of lignosulfonate. Knowledge about the …
